Background: Over 60% of women with polycystic ovary syndrome (PCOS) are either overweight or obese but the natural history of weight gain in women with PCOS is not well understood. We aim to examine the natural history of weight gain in women with and without diagnosed PCOS from birth until adulthood.
Methods: We performed a longitudinal analysis on 227 females of the Western Australian Pregnancy Cohort (Raine) Study where 66 females were diagnosed with PCOS using the Rotterdam Criteria. Anthropometric measurements were collected by trained researchers at birth and ages 1, 2, 3, 5, 8, 10, 14, 16, 20 and 22. The primary outcome was body mass index (BMI). T-tests and χ2 tests were used to examine the differences between groups. Longitudinal analysis of BMI was performed using Generalized Estimating Equations using PCOS on time and hyperandrogenism on time as interaction terms. Regression models were adjusted for parental BMI, family income, age of menarche, employment history, smoking and relationship status.
Results: Cross-sectional analysis showed that compared to women without PCOS, women with PCOS had higher BMI from age 14 onwards. Compared to women with non-hyperandrogenic PCOS, women with hyperandrogenic PCOS had higher BMI from year 8 onwards. In longitudinal analysis, significant interaction was detected between PCOS and time (Wald test <0.001) in the overall population and between hyperandrogenism and time (Wald test <0.001) in women with PCOS. Adjusted regression showed that women with and without PCOS had similar trend for BMI gain but significantly higher BMI gain occurred in women with PCOS from age 14 onwards. In women with PCOS, adjusted regression showed that women with hyperandrogenism had higher BMI gain from age 14 onwards.
Conclusion and relevance: Excessive weight gain in women with PCOS occurred after puberty and hyperandrogenism status is predictive of excessive weight gain.